Immersion heater



April 1929 J. c. wooDsoN 1,709,645

IMMERS ION HEATER Filed Nov. 30, 1927 INVENTOR James C. h/ooc/sonATTORNEY Patented Apr. 16 1929.

UNITED STATES PATENT OFFICE.

JAMES C, WOODSON, OF MANSFIELD, OHIO, ASSIGNOR TO WESTINGHOUSE ELECTRIC& MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

IMMERSION HEATER.

Application filed November 30, 1927. Serial No. 2363834..

My invention relates to melting pots and more particularly to anelectric heating means therefor.

It is an object of my invention to provide,

in .conjunction with a melting pot, an electrical-resistance heatingunit adapted to be immersed therein, and improved means for effectingthe electrical circuit connections for said unit, whereby theconnections are protected against injury and contamination incident tooperation of the heater.

A further object of my invention is to provide, in an electrical heatingunit adapted to be immersed in a melting pot and having an outlet boxsecured to an extremity thereof, selective means for securing said boxto said unit whereby the outlet opening thereof may be positioned beyondthe rim of said pot, irrespective of the Width of said rim.

heating unit comprising an electric-resistance element and leadstherefor cast into a-body of metal, and terminals secured to said leadsprojecting beyond the cast-metal portion. The unit is so proportionedthat, when in operative position immersed in a meltin pot, theresistance element is adjacent to thebottom of the pot and the castportion surrounding the leads extends over the rim thereof. I provide,further, a terminal-outlet box secured to the upper extremity of saidunit in a plurality of positions, selectively, to position the outletopening thereof beyond the pot rim, thereby permitting the use of theunit in conjunction with potshaving rims of various widths.

In the drawing: I

Figure 1 is an assembly, in elevation, of a melting pot and an immersionheater embodying my invention.

Fig.2 is a view, in vertical section, of the structure shown in Fig. 1,portions of the pot being broken away.

Fig. 3 is a plan view of the heating element shown in Fig. 2, with theoutlet box therefor shown in section.

Referring to the drawing, I have shown a melting pot 2 of the usual typewherein a flanged pot or crucible 4, of suitable heat-resistantmaterial, is enclosed by an annular wall 6 of refractory heat-insulatingbrick and a quantity of mineral wool 8 disposed between the pot andwall.

Since the particular construction of the melting pot constitutesno partof the present invention, further description thereof is not deemednecessary.

Referring more particularly to Figs. 2 and 3, the heating unit comprisesa coil 10 and leads 12 of electrical-resistance material covered by asuitable refractory insulation, and abody of metal cast therearoundforming a rugged unitary structure. In the present embodiment, I preferto employ cast iron for the body of the heater but obviously, othermetals may be employed if desired.

The portion 14 of the cast-metal body sur rounding the coiled resistor10, is provided with fins 16 and 18 cast integral therewith, to increasethe\heatradiating area thereof.

The fin 18 extends along the elongated portion 20 to increase theradiating area and to effect the structural reinforcement thereof.

The elongated portion 20 of the cast body,

enclosing the leads 12, is of substantially L- shape to permit the upperextremity thereof to. extend above and over the rim of pot 4, and besupported thereby. A boss 21, cast integral with the portion 20,constitutes a bearing point therefor in engagement with the pot rim.

The leads 12 are brought out through the end of the portion 20 and areprovided with terminals 22 for making the electrical circuit connectionsfor the heating unit.

Adjacent to the upper extremity of the elongated portion 20, areprovided a plurality of spaced annular grooves 24,25 and 26, coaxialtherewith, adapted to cooperate selectively with an opening in an outletbox 30, as

hereinafter described.

The outlet box 30 is of the usual construction wherein the box is formedin two halves adapted to be removably secured together in operativerelation. A semicircular opening, of a diameter substantially equal tothe diameter of the grooves 24, 25 and 26, is formed in the end wall ofeach half of the box, so

that the box may be clamped selectively in engagement witheither of thethree grooves.

Adjacent to the other end of the box, and preferably in the lowerlongitudinal face thereof are formed outlet openings adapted to receivetherethrough the leads 32 of the energizing circuit and suitablebushings 34, in a manner well known in theart.

If the heater bodv is of cast iron, the heater will tend to oat, ifimmersed in a bath of molten lead, because of the difference in thespecific gravities of the two metals. In order to obviate thisdifliculty, I provide a clamp 36 of substantially U-shape removablysecured to the pot rim and surrounding the horizontally extendingportion of the extension 20.

v In operation, the heater is positioned in the container, or meltingpot, with the portion 14 thereof resting upon the bottom of the pot andthe upper end of the elongated portion hooked over the pot rim, with theboss 21 resting thereupon. The lower half of the outlet box is thenpositioned selectively in one of the grooves 24, 25 or 26, dependinguponthe Width of the pot rim, to bring the outlet opening of the box beyondthe side wall of the pot. The power leads are then inserted through theoutlet openings and electrically connected to the terminals 22. The boxis then closed by clamping the upper half thereof to the lower half inoperative relation.

By my invention, I have provided an improved means for effecting theelectrical connection of an electrical heating element to a suitableenergizing circuit, whereby the electrical connections are completelyenclosed and protected against contamination incident to operation ofthe heater, and whereby the terminal connections and circuit leads areremoved, as far as practicable, from the operative portion of theheating element.

As above pointed out, the structure of the melting pot is purelyillustrative, and, quite obviously, various other applications of anelectric heater embodying my invention may be resorted to and be withinthe scope of the present invention.

On the other hand, while I have shown a heater of the castin type,clearly, my invention is also applicable to other types ofelectrical-resistance heaters, wherein the protection of the electricalconnections thereof is desired.

Various modifications may be made in my invention Without departing fromthe spirit and scope thereof and I desire, therefore, that only suchlimitations shall be placed thereon as are imposed by the prior art orare set forth in the appended claims.

I claim as my invention:

1. An electrical heating unit comprising an electrical resistor andterminals therefor, a terminal box, and means for securing said box tosaid unit selectively in a plurality of positions and in operativerelation to said terminals.

2. An electric heater comprising an insulated electrical-resistanceheating element and a body of cast metal surrounding said element,terminal connections for said element projecting beyond said cast-metalbody, a terminal outlet box enclosing said terminals, and means forsecuring said box to said cast-metal portion selectively in a pluralityof positions longitudinally thereof.

3. An immersion heater comprising an electrical resistor, leadstherefor, and terminals secured to said leads, a body of metal castabout said resistor and an elongated portion cast integral therewithsurrounding said leads, an outlet box and selective means for securingsaid box to said elongated por tion in a plurality of positionslongitudinally thereof, whereby said terminals and selected portions ofsaid extension are enclosed thereby.

4. An electrical immersion heater comprising an electrically insulatedresistance heating element, terminal leads therefor, and a body of metalcast about said element and leads; terminals secured to said leadsbeyond said cast metal portion, a terminal outlet box and means forselectively securing said box to said cast metal portion in a pluralityof positions and in operative relation to said terminals.

5. In an immersion heater for a melting pot comprising an electricalresistor, leads therefor extending above the rim of said pot, terminalssecured to the ends of said leads, and a body of metal cast about saidresistor and leads; means for making electrical connections to saidresistor comprising an outlet box enclosing said terminals and means forselectively securing said box to said body portion in a plurality ofpositions longitudinally thereof to position an outlet opening thereofbeyond the rim of said pot.

In testimony whereof, I have hereunto subscribed my name this 19 day ofNovember 1927.

JAMES C. l/VOODSON.

